Mucinous Carcinoma of the Ovary With Signet Ring Cells: Primary Tumor or Metastatic Spread?

We describe a case of mucinous carcinoma of the ovary with signet ring cell morphology presenting in a young woman. No primary tumor was identified radiologically or endoscopically, and the patient is clinically well 2 years after the initial ovarian tumor. The presence of signet ring cells in a primary mucinous carcinoma is unusual, and in the first instance metastasis from a separate primary tumor should be excluded. Features differentiating a primary ovarian carcinoma from a metastatic tumor spreading from a separate primary are considered.